DLC is the acronym for Diamond-like Carbon Coating. DLC coating is made from carbon atoms, and it is the hardest coating that can be applied on knife blades and other products like guns and watches. The hardness of DLC coating is practically similar to what you will get from natural diamond.
The DLC blade coating is pitch black, therefore, it does provide anti-reflection properties for knife enthusiasts and people in the military who might need to conceal their weapons for obvious reasons.
Knife users who purchase DLC coated knives are keen on the pitch-black appearance and performance. It provides excellent wear resistance, low friction, and enhances the hardness of the blades.
What’s more, DLC has been on the market for more than 60 years now. You will find different companies offering DLC coating services throughout the United States. Some knife brands like Kershaw also apply DLC Coating on their premium knives.
Properties of DLC coating
DLC is part of the carbon family, and its composition makes it harder than most materials used for knife coating. To come to the point, the mechanical properties of DLC coating in relation to hardness and elasticity make it a good choice for knife coating.
DLC offers low friction performances, associated with the absence of adhesive forces between moving diamond surfaces. The combination of high hardness and low friction makes DLC coating a perfect coating choice for the knife industry and in the manufacture of brakes, bearings, seals, and gears.
The coating offers excellent corrosion resistance thanks to its chemical and physical properties. This property makes it suitable for knife coating and especially for knives manufactured to be used in highly corrosive environments.
The texture of DLC coating can either be smooth or rough, describing its surface properties. A smooth coating offers good sliding abilities and improves the knife’s performance. Therefore, the coating process aims to achieve a smooth surface.
Pros of DLC coating
- High hardness
The main benefit of DLC is its high hardness because it improves the edge retention, wear resistance, and life span of knives. It is estimated that the hardness of DLC is 75+ HRC, which is harder than the hardest knife steels like REX 121 or Maxamet, which are about 70HRC.
Therefore, this coating can enhance knives’ performance made from low-carbon steel.
- Excellent wear resistance
The DLC coating is highly resistant to wear and abrasion. This ensures the smooth movement of knife blades during operation and improves their longevity even with frequent sharpening and challenging applications.
- Low Coefficient of friction
DLC also stands out among other coatings because it possesses a low friction coefficient, which increases the efficiency of knives and other cutting tools. Because of reduced friction, the tools operate at high speed and with less sticking.
Also, the cost of production in industries that use cutting tools coated with DLC is low because they spend less on lubricants, and the production process takes less time.
DLC black coating gives a knife blade suitable anti glaring property due to its consistent and uniform pitch-black appearance. This will be much suitable for the persons in the military as it makes the knife blade more concealable.
- Superior corrosion resistance
Another benefit of DLC coating is that it is corrosion resistant; therefore, you can use DLC-coated knives in highly corrosive environments without the fear of rust or stains. To improve the corrosion resistance, the thickness of the coating must be increased.
- Chemically inactive
Another essential advantage of DLC coating is that it does not react with alkaline or acids. Therefore, when used on knives, the coating is food safe because it will never react to any ingredients.
Cons of DLC coating
- Poor adhesion
The adhesion challenge in DLC coating results from extra thickness, which increases internal stress resulting in cracking. To solve this challenge, a multilayer coating technique is used.
Extra care and preparation need to be taken when applying DLC. A DLC will not stick on existing paint. Paint stripping and additional preparation like sandblasting and bead blasting will significantly enhance the adhesion of DLC to your knife blade.
- Low heat tolerance
DLC coatings start to degrade at 400 degrees Celsius; therefore, it is not a good choice for environments of high processing temperatures.
It also has to be applied to a knife at a temperature of 400 degrees Fahrenheit or lower to not affect the blade’s heat treatment.
- Does not cover or hide scratches
It is worth noting that if you are applying DLC on a used knife with deep grooves or scratches, DLC will only follow the blade’s finish; it will not cover the scratches.
For the scratches to be completely hidden, preparing the knife blade like sanding or bead blasting will have to be done.
Is DLC good for knife coating?
DLC coating is ideal for knives because of its high hardness, excellent wear resistance, and superior corrosion resistance. These properties improve the performance and lifespan of knives.
Cerakote vs. DLC knife coating
The Cerakote and DLC coating both offer improved performance to a knife. The Cerakote is extremely corrosion resistant and will beat a DLC knife coat in a corrosion test.
In terms of wear resistance, the DLC coating will show no signs of wear even when the knife is used in tough applications like wood batoning. A Cerakote will show signs of minor scratches.
Is DLC coating safe?
Yes, DLC coating is perfectly safe even for use in kitchen knives. The element is chemically inactive and will not react with acid or base substances found in foods. DLC coating is also highly resistant to corrosion and rust, making it food safe. Studies have also shown that DLC coating is biocompatible and will not react with tissue or bone cells.
Does DLC coating wear off?
DLC knife coating does not wear off even after repeated use in demanding applications when applied correctly. DLC coating has been used in highly demanding applications, apart from the knife industry. It is constantly used in the coating of camshafts in F1 engines. This should explain how capable it is to resist wearing off.
How much does DLC coating cost?
DLC coating services are not as expensive as one may think. The cost will largely depend on the size of the blade and the type, i.e., folder or fixed knife. The manufacturer’s way of applying the coating will also determine the price. Generally, a 6″ to 10″ inch blade will cost about $100-$150.
Preparation services like disassembly, paint stripping, beading, and sandblasting will attract extra charges for most DLC coating services.
My name is Jonathan M, and I’m a passionate Mechanical Engineer, a knife enthusiast, and the author of this website. I have a bachelor's degree in Mechanical engineering with a specialization in material science. I am particularly interested in researching knife steel, knife properties, and brands. I hope you will find value in the articles on this website. Contact me if you have any questions or input!